This invention relates broadly to the art of hand tools, and more particularly to pliers-like tools for installing and removing snap rings.
Snap ring removing tools, which generally involve pliers-like implements whose jaws expand when handgrips are squeezed together, usually include pins, or narrow projections, for insertion into holes normally found on opposite sides of snap-ring "breaks". After such insertion, the hand-grips are urged together to expand the jaws and the engaged snap rings so that the snap rings can be installed or removed from slots about shafts. Such prior art snap ring tools are disclosed in U.S. Pat. Nos. 2,455,165 to Feitl, 3,371,401 to Deguy, 3,650,008 to Plouffe, and 3,990,137 to Kulba et al. The Deguy patent also discloses having the pins engage the break edges of snap rings which do not have holes.
A difficulty with such devices is that when snap rings are expanded therewith, they tend to swivel, or rotate, thereby requiring that they be expanded to an even larger amount before they can be easily removed from, or mounted in, snap-ring slots. When snap rings are expanded too much, they become fatigued or strained, which often renders them inappropriate for further use. Further, because of space requirements, it is often difficult to expand snap rings very much. Thus, it is an object of this invention, to provide a pliers-like implement for removing snap rings which impedes the snap rings from swivelling, or rotating during expansion thereof but yet which does not require complicated structure. The aforementioned Deguy patent discloses a second pair of jaws that are claimed to keep the snap rings from warping and which limit expansion of the rings, but the Deguy device is relatively complex, would be awkward to use, and has a limited ability to prevent warping.
Several suggestions have been made for employing similar prior-art implements which involve using grooves in jaws of the implements to engage opposite "break" edges of the clips or rings. Examples of these suggestions are found in U.S. Pat. Nos. 1,100,486 to Merliss and 3,254,649 to Wood. Although these implements may be useful for the particular applications for which they are disclosed (Merliss is a device for removing piston rings and Wood is a device for removing skin clips), they are not useful for removing snap rings because of difficulties involved in placing the implements in proper positions for removing the snap rings. Further, these implements would not positively hold the snap rings against disengagement. Thus, it is a further object of the invention to provide a pliers-like, snap-ring implement which can be relatively easily brought into positive engagement with snap rings and which thereafter retains them by positive engagement during manipulations of the snap rings.
It is a further object of this invention to provide such a pliers-like, expanding-jaw tool which is relatively uncomplicated to manufacture and use.